Motor vehicle tail gas detection method based on sensor

Abstract

The invention relates to the technical field of tail gas detection, in particular to a motor vehicle tail gas detection method based on a sensor, which comprises the following steps: collecting tail gas component data in real time and obtaining a tail gas emission value through a sensor module arranged at an outlet of a motor vehicle exhaust pipeline; synchronously acquiring operation parameters and environment parameters of the motor vehicle through a data acquisition module; the running states of the motor vehicle are determined according to the vehicle speed and the vehicle speed variation, a corresponding preset reference value is set for each running state, and an exhaust emission evaluation value is determined according to the preset reference values; judging whether the exhaust emission meets a preset standard or not according to the exhaust emission evaluation value; if yes, the detection frequency is improved according to the comprehensive influence coefficient; if not, the tail gas emission value is corrected according to the environment evaluation coefficient, or the response grade is determined according to the composite risk index, and the corresponding response scheme is determined based on the response grade, so that the tail gas detection accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of exhaust gas detection, and in particular to a sensor-based motor vehicle exhaust gas detection method. Background Art

[0002] With the acceleration of global urbanization and the continuous increase in the number of motor vehicles, motor vehicle exhaust emissions have become one of the main sources of urban air pollution and greenhouse gas growth. Traditional fuel vehicles generate power through the combustion of fossil fuels in internal combustion engines. Their exhaust mainly contains harmful substances such as carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and particulate matter (PM), which seriously threaten the health of the human respiratory system and aggravate environmental problems such as photochemical smog and acid rain.

[0003] Chinese patent application publication number: CN116643002A, discloses a vehicle exhaust detection method, belongs to the technical field of highway traffic flow prediction, a vehicle exhaust detection method, including the following steps: step 1, enter the basic information of the vehicle, step 2, retrieve the information of the tested vehicle through the database, step 3, test the HC content in the exhaust gas analyzer, detect whether there is exhaust gas residue in the current exhaust gas analyzer, if there is no HC residue; step 4, detect the current engine temperature of the vehicle, step 5, insert the exhaust gas probe when it reaches 80°, and test the exhaust emission concentration at this time, step 6, if the sum of CO and HC concentrations is greater than 6%, insert the exhaust gas probe into the exhaust pipe and continue to detect, otherwise stop the detection; step 7, increase the car speed to 25km / h, perform a working condition test, if the exhaust gas concentration content is greater than the specified limit, end.

[0004] However, the prior art has the following problems: the traditional exhaust gas detection method may have a variety of interference factors, such as vehicle driving status, environment, etc., which may lead to inaccurate detection results. Summary of the invention

[0005] To this end, the present invention provides a sensor-based motor vehicle exhaust gas detection method to overcome the problem in the prior art that exhaust gas detection results are inaccurate due to interference factors such as vehicle driving status and environment.

[0006] To achieve the above object, the present invention provides a sensor-based motor vehicle exhaust detection method, comprising: The sensor module installed at the outlet of the motor vehicle exhaust pipe collects exhaust gas composition data in real time and obtains exhaust gas emission values; The operating parameters and environmental parameters of the motor vehicle are synchronously acquired through the data acquisition module, wherein the operating parameters include vehicle speed, vehicle speed change, start-stop frequency and operating time, and the environmental parameters include atmospheric pressure and ambient temperature; Determine the running state of the motor vehicle according to the vehicle speed and the speed change, set a corresponding preset reference value for each running state, and determine the exhaust emission evaluation value according to the preset reference value; Determine whether the exhaust emissions meet the preset standards according to the exhaust emission evaluation value; When the conditions are met, the inspection frequency will be increased according to the comprehensive impact coefficient; When it does not meet the requirements, the tail gas emission value is corrected according to the environmental assessment coefficient, or the response level is determined according to the composite risk index and the corresponding response plan is determined based on the response level.

[0007] Furthermore, the sensor module includes an electrochemical sensor for detecting CO and HC, a non-spectroscopy infrared sensor for detecting NOx, and a laser particle sensor for detecting particulate matter.

[0008] Further, the running state of the motor vehicle is determined according to the vehicle speed and the speed change, wherein: When the vehicle speed is the initial speed and the engine is in the running state, determining that the running state of the motor vehicle is the first running state; When the vehicle speed is not the initial speed and the vehicle speed change is less than a preset change, determining that the motor vehicle operating state is the second operating state; When the vehicle speed change is greater than or equal to the preset change, it is determined that the motor vehicle operating state is the third operating state.

[0009] Furthermore, under the condition that the exhaust emission evaluation value is less than the first preset evaluation value, it is determined that the exhaust emission meets the preset standard, and the exhaust gas detection frequency is increased according to the comprehensive influence coefficient.

[0010] Further, under the condition that the exhaust emission evaluation value is greater than or equal to the first preset evaluation value, it is determined that the exhaust emission does not meet the preset standard, and, When the exhaust emission evaluation value is greater than or equal to the first preset evaluation value and less than the second preset evaluation value, the exhaust emission value is corrected according to the environmental evaluation coefficient, wherein the environmental evaluation coefficient is determined by the atmospheric pressure and the ambient temperature; When the exhaust emission evaluation value is greater than or equal to the second preset evaluation value, a response level is determined according to the composite risk index and a corresponding response plan is determined based on the response level.

[0011] Furthermore, the exhaust gas detection frequency is positively correlated with the comprehensive influence coefficient, wherein the comprehensive influence coefficient is jointly determined by the traffic density and the start-stop conditions of motor vehicles.

[0012] Furthermore, several correction methods are provided for the tail gas emission value, and each correction method has a different correction range for the tail gas emission value.

[0013] Furthermore, the composite risk index is determined by the operating time, the start-stop frequency and the dynamic difference change rate.

[0014] Further, a response level is determined according to the composite risk index, wherein: If the composite risk index is less than the first preset risk index, the response level is determined to be level three; If the composite risk index is greater than or equal to the first preset risk index and less than the second preset risk index, the response level is determined to be level 2; If the composite risk index is greater than or equal to the second preset risk index, the response level is determined to be level one.

[0015] Further, a corresponding response scheme is determined based on the response level, wherein: If the response level is level one, it is an emergency response and a mandatory speed limit is imposed on motor vehicles; If the response level is level 2, it is a medium response, and a warning is issued to the motor vehicle, and high-frequency exhaust data transmission is enabled; If the response level is level three, it is a low-level response and the detection cycle of the motor vehicle is shortened.

[0016] Compared with the prior art, the beneficial effect of the present invention lies in that the present invention collects exhaust gas composition data in real time through the sensor module, and obtains the operating parameters and environmental parameters of the motor vehicle in combination with the data acquisition module, thereby overcoming the problem of inaccurate detection results caused by various interference factors in the prior art and improving the accuracy of exhaust gas detection.

[0017] Furthermore, the present invention determines the operating state of a motor vehicle based on the vehicle speed and the change in vehicle speed, determines the exhaust emission evaluation value based on the preset reference value under different operating states, and dynamically adjusts the exhaust emission evaluation standard according to different operating conditions, so that the detection result is closer to the actual situation.

[0018] Furthermore, when the exhaust emissions meet the preset standards, the present invention increases the detection frequency according to the comprehensive influence coefficient. While ensuring the detection accuracy, the comprehensive influence coefficient is determined according to the traffic density and the start and stop conditions of the motor vehicle, thereby increasing the detection frequency under complex vehicle conditions and making the detection more accurate.

[0019] Furthermore, when the exhaust emissions do not meet the preset standards, the present invention can correct the exhaust emission values ​​according to the environmental evaluation coefficient, or determine the response level according to the composite risk index and adopt a corresponding response plan, so as to make timely and effective treatment for different situations and reduce the negative impact of exhaust emissions on the environment.

[0020] Furthermore, the present invention determines the response level according to the composite risk index, and takes corresponding measures to ensure timely and effective control of exhaust emission risks. Through the graded response mechanism, it is possible to flexibly respond to exhaust emission problems of different degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a flow chart of a sensor-based motor vehicle exhaust detection method according to an embodiment of the present invention; Figure 2 A flow chart for determining the operating state of a motor vehicle according to an embodiment of the present invention; Figure 3 A flowchart of an embodiment of the present invention for determining whether exhaust emissions meet preset standards; Figure 4 The present invention is a flowchart of determining a response level and a response plan according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0024] It should be pointed out that the data in this embodiment are obtained by comprehensive analysis and evaluation of the historical test data and the corresponding historical test results of the present invention in the three months before this test. It can be understood by those skilled in the art that the present invention can determine the above parameters for a single item by selecting the highest proportion of values ​​as the preset standard parameters according to the data distribution, using weighted summation to use the obtained values ​​as the preset standard parameters, substituting each historical data into a specific formula and using the values ​​obtained by the formula as the preset standard parameters or other selection methods, as long as the present invention can clearly define different specific situations in the single determination process through the obtained values.

[0025] See also Figures 1 to 4 As shown, they are respectively a flow chart of a motor vehicle exhaust detection method based on a sensor according to an embodiment of the present invention; a flow chart of determining a motor vehicle operating state according to an embodiment of the present invention; a flow chart of determining whether exhaust emissions meet preset standards according to an embodiment of the present invention; and a flow chart of determining a response level and a response plan according to an embodiment of the present invention.

[0026] The sensor-based motor vehicle exhaust gas detection method according to the embodiment of the present invention includes: Step S1, collecting exhaust gas composition data in real time and obtaining exhaust gas emission values ​​through a sensor module installed at the exhaust pipe outlet of the motor vehicle; Step S2, synchronously acquiring the operating parameters and environmental parameters of the motor vehicle through the data acquisition module, wherein the operating parameters include vehicle speed, vehicle speed change, start-stop frequency and operating time, and the environmental parameters include atmospheric pressure and ambient temperature; Step S3, determining the running state of the motor vehicle according to the vehicle speed and the speed change, setting a corresponding preset reference value for each running state, and determining the exhaust emission evaluation value according to the preset reference value; Step S4, determining whether the exhaust emissions meet the preset standards according to the exhaust emission evaluation value; Step S5a, when the conditions are met, increasing the detection frequency according to the comprehensive influence coefficient; Step S5b: when it does not meet the requirements, the tail gas emission value is corrected according to the environmental assessment coefficient, or the response level is determined according to the composite risk index and a corresponding response plan is determined based on the response level.

[0027] Specifically, the sensor module is fixed on the chassis of the motor vehicle near the outlet of the exhaust pipe. The sensor module is connected to an exhaust gas absorption pipe, and the other end of the exhaust gas absorption pipe is fixed inside the outlet of the exhaust pipe.

[0028] Specifically, the tail gas absorption tube can be, for example, a stainless steel tube, without any specific limitation, and only needs to meet the requirements of high temperature resistance and corrosion resistance.

[0029] Specifically, the data acquisition module includes a first sensor group arranged inside the motor vehicle for acquiring operating parameters of the motor vehicle and a second sensor group arranged outside the motor vehicle for acquiring environmental parameters. Specifically, the first sensor group includes a wheel speed sensor for acquiring vehicle speed and vehicle speed change, a monitoring sensor for acquiring start-stop frequency and running time, and a crankshaft position sensor for acquiring engine speed.

[0030] Specifically, the second sensor group includes a pressure sensor for acquiring atmospheric pressure and a temperature sensor for acquiring ambient temperature.

[0031] Specifically, the sensor module includes an electrochemical sensor for detecting CO and HC, a non-spectral infrared sensor for detecting NOx, and a laser particle sensor for detecting particulate matter.

[0032] Specifically, the tail gas absorption tube is connected to the electrochemical sensor, the non-spectral infrared sensor and the laser particle sensor respectively, and a solenoid valve is arranged at the air inlet of each sensor.

[0033] Specifically, the working process of the sensor module includes: the exhaust absorption tube extracts a preset amount of exhaust gas and passes it into the electrochemical sensor, non-spectroscopic infrared sensor and laser particle sensor respectively. Each sensor analyzes the exhaust gas sample and converts the concentration of CO, HC, NOx and particulate matter in the exhaust gas into electrical signals respectively, and finally transmits these electrical signals to the data management system.

[0034] Specifically, the preset amount is, for example, 10 mL, which is not specifically limited.

[0035] Specifically, the running state of the motor vehicle is determined according to the vehicle speed and the speed change, wherein: When the vehicle speed is an initial speed of 0 and the engine is in a running state, determining that the running state of the motor vehicle is a first running state; When the vehicle speed is not the initial speed and the vehicle speed change is less than a preset change of 5 km / h, determining that the motor vehicle operating state is the second operating state; When the vehicle speed change is greater than or equal to the preset change, it is determined that the motor vehicle operating state is the third operating state.

[0036] In the embodiment of the present invention, the initial speed is 0, and the preset change is 5 km / h, but the above values ​​are not limited thereto, and those skilled in the art may adjust the values ​​according to actual needs.

[0037] Specifically, if the engine speed is not 0, it means that the engine is in a running state.

[0038] Specifically, the first operating state is a stationary state, the second operating state is a uniform speed state, and the third operating state is a variable speed state.

[0039] Specifically, the preset reference value in the first motion state is a first preset reference value of 0.12, the preset reference value in the second motion state is a second preset reference value of 0.15, and the preset reference value in the third motion state is a third preset reference value of 0.18.

[0040] In the embodiment of the present invention, the first preset reference value is 0.12, the second preset reference value is 0.15, and the third preset reference value is 0.18, but the above values ​​are not limited thereto, and those skilled in the art may adjust the values ​​according to actual needs.

[0041] Specifically, the exhaust emission value is calculated by the following formula, , in the formula, C is the exhaust emission value, is the weight coefficient of NOx, set , is the concentration of NOx (g / km); is the weight coefficient of PM, set , is the concentration of PM; is the weight coefficient of CO, set , is the concentration of CO; is the weight coefficient of HC, set , is the concentration of HC.

[0042] Specifically, the exhaust emission evaluation value is the difference between the real-time exhaust emission value and the preset reference value.

[0043] Specifically, under the condition that the exhaust emission evaluation value is less than the first preset evaluation value of 0.005, it is determined that the exhaust emission meets the preset standard, and the exhaust gas detection frequency is increased according to the comprehensive influence coefficient.

[0044] Specifically, under the condition that the exhaust emission evaluation value is greater than or equal to the first preset evaluation value, it is determined that the exhaust emission does not meet the preset standard, and, When the exhaust emission evaluation value is greater than or equal to the first preset evaluation value and less than 0.01 of the second preset evaluation value, the exhaust emission value is corrected according to the environmental evaluation coefficient, wherein the environmental evaluation coefficient is determined by the atmospheric pressure and the ambient temperature; When the exhaust emission evaluation value is greater than or equal to the second preset evaluation value, a response level is determined according to the composite risk index and a corresponding response plan is determined based on the response level.

[0045] In the embodiment of the present invention, the first preset evaluation value is 0.005, and the second preset evaluation value is 0.01, but the above values ​​are not limited thereto, and those skilled in the art may adjust the values ​​according to actual needs.

[0046] Specifically, the exhaust gas detection frequency is positively correlated with the comprehensive impact coefficient, among which, If the comprehensive influence coefficient is less than the preset influence coefficient of 1.3, the exhaust gas detection frequency is adjusted to a corresponding value using the first frequency adjustment coefficient of 1.25; If the comprehensive influence coefficient is greater than or equal to the preset influence coefficient, the exhaust gas detection frequency is adjusted to a corresponding value using a second frequency adjustment coefficient of 1.5.

[0047] In an embodiment of the present invention, the preset influence coefficient is 1.3, the initial exhaust gas detection frequency is set to 5 times / hour, the first frequency adjustment coefficient is 1.25, and the second frequency adjustment coefficient is 1.5, but the above values ​​are not limited to this. Technical personnel in this field can adjust the value according to actual needs.

[0048] Specifically, the comprehensive impact coefficient is determined by the traffic density and the start-stop situation of motor vehicles, and is calculated by the following formula: In the formula, E is the comprehensive influence coefficient, α is the first weight coefficient, set α=0.6, D is the traffic density, Dy is the traffic density threshold, set Dy=20 vehicles / km, β is the second weight coefficient, set β=0.4, S is the start-stop frequency, Sy is the start-stop frequency threshold, set Sy=5 times / hour.

[0049] Specifically, the traffic density is determined by a vehicle-mounted GPS positioning device.

[0050] Specifically, there are several correction methods for the tail gas emission value, and each correction method has a different correction range for the tail gas emission value, among which: If the environmental assessment coefficient is less than the first preset environmental assessment coefficient of 1.2, the exhaust emission value is corrected to the corresponding value using the first correction coefficient of 0.99; If the environmental evaluation coefficient is greater than or equal to the first preset environmental evaluation coefficient and less than the second preset environmental evaluation coefficient of 1.8, the exhaust emission value is corrected to the corresponding value using the second correction coefficient of 0.97; If the environmental evaluation coefficient is greater than or equal to the second preset environmental evaluation coefficient, the exhaust emission value is corrected to a corresponding value using a third correction coefficient of 0.95.

[0051] In the embodiment of the present invention, the first preset environment evaluation coefficient is set to 1.2, and the second preset environment evaluation coefficient is set to 1.8, but the above values ​​are not limited thereto, and those skilled in the art may adjust the values ​​according to actual needs.

[0052] Specifically, the environmental assessment coefficient is calculated by the following formula: In the formula, G is the environmental assessment coefficient, P 0 is the atmospheric pressure threshold, set P 0 =101.3 kPa, P is atmospheric pressure, T is ambient temperature, T 0 is the ambient temperature threshold, set T 0 =20℃.

[0053] Specifically, the composite risk index is determined by the operating time, start-stop frequency and tail gas emission value change rate, and is calculated by the following formula: , where R is the composite risk index, is the first weight coefficient, set =0.35, T is the running time (hours), is the second weight coefficient, set =0.33, S is the start-stop frequency (times / minute), is the third weight coefficient, set =0.32, is the rate of change of exhaust emission value (%).

[0054] Specifically, the exhaust emission value change rate is the ratio of the exhaust emission evaluation value to a preset reference value.

[0055] Specifically, the response level is determined according to the composite risk index, wherein: If the composite risk index is less than the first preset risk index of 0.35, the response level is determined to be level three; If the composite risk index is greater than or equal to the first preset risk index and less than 0.7 of the second preset risk index, the response level is determined to be level 2; If the composite risk index is greater than or equal to the second preset risk index, the response level is determined to be level one.

[0056] In the embodiment of the present invention, the first preset risk index is set to 0.35, and the second preset risk index is set to 0.7, but the above values ​​are not limited thereto, and those skilled in the art may adjust the values ​​according to actual needs.

[0057] Specifically, a corresponding response scheme is determined based on the response level, wherein: If the response level is level one, it is an emergency response and a mandatory speed limit is imposed on motor vehicles; If the response level is level 2, it is a medium response, and a warning is issued to the motor vehicle, and high-frequency exhaust data transmission is enabled; If the response level is level three, it is a low-level response and the detection cycle of the motor vehicle is shortened.

[0058] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sensor-based motor vehicle exhaust detection method, characterized in that: include: The sensor module installed at the outlet of the motor vehicle exhaust pipe collects exhaust gas composition data in real time and obtains exhaust gas emission values; The operating parameters and environmental parameters of the motor vehicle are synchronously acquired through the data acquisition module, wherein the operating parameters include vehicle speed, vehicle speed change, start-stop frequency and operating time, and the environmental parameters include atmospheric pressure and ambient temperature; Determine the running state of the motor vehicle according to the vehicle speed and the speed change, set a corresponding preset reference value for each running state, and determine the exhaust emission evaluation value according to the preset reference value; Determine whether the exhaust emissions meet the preset standards according to the exhaust emission evaluation value; When the conditions are met, the inspection frequency will be increased according to the comprehensive impact coefficient; When it does not meet the requirements, the tail gas emission value is corrected according to the environmental assessment coefficient, or the response level is determined according to the composite risk index and the corresponding response plan is determined based on the response level.

2. The sensor-based motor vehicle exhaust detection method according to claim 1, characterized in that: The sensor module includes an electrochemical sensor for detecting CO and HC, a non-spectral infrared sensor for detecting NOx, and a laser particle sensor for detecting particulate matter.

3. The sensor-based motor vehicle exhaust detection method according to claim 1, characterized in that: The running state of the motor vehicle is determined according to the vehicle speed and the speed change, wherein: When the vehicle speed is the initial speed and the engine is in the running state, determining that the running state of the motor vehicle is the first running state; When the vehicle speed is not the initial speed and the vehicle speed change is less than a preset change, determining that the motor vehicle operating state is the second operating state; When the vehicle speed change is greater than or equal to the preset change, it is determined that the motor vehicle operating state is the third operating state.

4. The sensor-based motor vehicle exhaust detection method according to claim 1, characterized in that: Under the condition that the exhaust emission evaluation value is less than the first preset evaluation value, it is determined that the exhaust emission meets the preset standard, and the exhaust gas detection frequency is increased according to the comprehensive influence coefficient.

5. The sensor-based motor vehicle exhaust detection method according to claim 4, characterized in that: Under the condition that the exhaust emission evaluation value is greater than or equal to the first preset evaluation value, it is determined that the exhaust emission does not meet the preset standard, and, When the exhaust emission evaluation value is greater than or equal to the first preset evaluation value and less than the second preset evaluation value, the exhaust emission value is corrected according to the environmental evaluation coefficient, wherein the environmental evaluation coefficient is determined by the atmospheric pressure and the ambient temperature; When the exhaust emission evaluation value is greater than or equal to the second preset evaluation value, a response level is determined according to the composite risk index and a corresponding response plan is determined based on the response level.

6. The sensor-based motor vehicle exhaust detection method according to claim 4, characterized in that: The exhaust gas detection frequency is positively correlated with the comprehensive impact coefficient, wherein the comprehensive impact coefficient is determined by the traffic density and the start and stop conditions of motor vehicles.

7. The sensor-based motor vehicle exhaust detection method according to claim 5, characterized in that: There are several correction methods for the exhaust emission value, and each correction method has a different correction range for the exhaust emission value.

8. The sensor-based motor vehicle exhaust detection method according to claim 5, characterized in that: The composite risk index is determined by the operating time, the start-stop frequency and the dynamic difference change rate.

9. The sensor-based motor vehicle exhaust detection method according to claim 8, characterized in that: The response level is determined according to the composite risk index, wherein: If the composite risk index is less than the first preset risk index, the response level is determined to be level three; If the composite risk index is greater than or equal to the first preset risk index and less than the second preset risk index, the response level is determined to be level 2; If the composite risk index is greater than or equal to the second preset risk index, the response level is determined to be level one.

10. The sensor-based motor vehicle exhaust detection method according to claim 9, characterized in that: A corresponding response scheme is determined based on the response level, wherein: If the response level is level one, it is an emergency response and a mandatory speed limit is imposed on motor vehicles; If the response level is level 2, it is a medium response, and a warning is issued to the motor vehicle, and high-frequency exhaust data transmission is enabled; If the response level is level three, it is a low-level response and the detection cycle of the motor vehicle is shortened.

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